Aircraft flight decks typically include multiple altimeters to display the altitude of the aircraft to the pilot or flight crew. The altimeter, as is generally known, provides an indication of the aircraft altitude as referenced to mean sea level (MSL), and is thus typically determined using static air pressure and an altimeter setting (or “reference pressure”). The static pressure is preferably sensed by one or more sensors, and the altimeter setting is entered by a user (e.g., pilot) via, for example, a baro-set knob or other user interface device. The altimeter setting that a user enters is typically either the local barometric air pressure or a standard barometric pressure (e.g., 29.92 in. Hg. or 1013 hPa). Typically, the altimeter setting is set to the local barometric air pressure when the aircraft flying below a predetermined transition altitude, and is set to the standard barometric pressure when flying above the transition altitude. This predetermined transition altitude may vary from airport to airport, country to country, and/or from flight jurisdiction to flight jurisdiction. In the United States this predetermined transition altitude is generally 18,000 feet MSL.
When an aircraft that is flying above the predetermined transition altitude is approaching its destination, the flight crew will typically receive the local barometric air pressure from the destination airport. This information may be supplied from the destination airport by air traffic control or other ground crew; however, it is more typically supplied via the Automatic Terminal Information Service (ATIS) broadcast from the destination airport. The local barometric air pressure may be received while the aircraft is still a considerable distance from the destination airport. Thus, the flight crew will most often store the local barometric air pressure using the baro-set knob on the aircraft's standby altimeter. Thereafter, when the aircraft transitions below the predetermined transition altitude, the flight crew sets the altimeter setting to the local barometric air pressure.
Although the above-described system and method of storing the local barometric air pressure is generally safe and reliable, it does suffer certain drawbacks. For example, if an aircraft does not include a standby altimeter or the standby altimeter is inoperable, then the flight crew may need to memorize the local barometric air pressure, write the local barometric air pressure on a kneeboard or other device, listen to the ATIS transmissions from the destination airport multiple times, or request that the ground crew supply the value just prior to descending below the transition altitude. All these alternatives can result in unneeded and unwanted distractions for the flight crew during aircraft descent.
Hence, there is a need for a system and method of at least selectively displaying a storing the local barometric air pressure that does not result in unneeded or unwanted distractions. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.